Universal Language Selector offers the following features on Wikimedia wikis:

User interface language selection for logged in users.

Web fonts

Input methods

How does Universal Language Selector determine which languages I may understand[edit]

ULS queries a service that determines your originating country based on your IP address. This is inaccurate in some cases. Based on the country code, most often spoken languages are suggested for you.

The "common languages" for a country are hard to determine as well. For this reason, they come from the Milkshake libraries which we aim to maintain with other interested software projects beyond MediaWiki/Wikimedia. Essentially, however, most of the data for it comes from Unicode (see CLDR for more info) and can be seen on the Territory-Language Information table. If you have suggestions to improve the languages currently suggested to you by ULS, first check if that table has the best data; if it can be improved, click "add new" for your country/language and propose changes. Unicode maintainers are helpful and no registration is required.

Keep in mind the CLDR definitions and remember to mention reliable sources for the specific data you propose, like for instance an official statistics bureau or a scientific survey (for literacy figures), or national and local laws (to prove a language can be used to communicate with a national/local administration).

On projects with language versions (Wikipedia, Wikibooks, Wikiversity, Wiktionary, Wikiquote, Wikivoyage, Wikinews, Wikisource) Universal Language Selector is visible as a cog icon in the menu area for interlanguage links. In Wikimedia projects without language versions (for example Wikimedia Commons, Meta-Wiki, Wikispecies and this wiki mediawiki.org), ULS is available as an icon in the personal toolbar at the top of the page.

Click the icon, make settings and confirm them to have the settings remain active.

A small keyboard icon will appear for all fields that allow text input. Select it to make changes to the settings.

The language used to display the MediaWiki interface messages can be changed using the Language Settings panel of ULS.

On Wikimedia projects, this feature is only available for logged-in users.

After logging in, you can open the Language Settings panel [on the sidebar or at the top] and navigate to the Language tab of the Display settings.

For quick selection, ULS will display a list of possible languages based on your location. You can click to select the language of your choice.

If the language you are looking for is not on the panel, you can click on the '...' button to open the longer list of languages to search and select.

A small popup (technically called "undo popover" or "tipsy") will also appear when ULS changes the language compared to your previous setting, so that you can more easily change again.
In some cases, a tooltip is displayed instead.

Do I need to be logged in to be able to change the Display language[edit]

Yes. The display language can only be changed by logged-in users.

If I change the Display language, will this change the language of the content on the page I am viewing[edit]

No. ULS does not change the language of the content on the page. It can be used to only change the interface language of MediaWiki (sometimes called "display language" in this FAQ).

However, the Translate extension, where installed, may be configured to redirect the user to existing translations of a page in some cases where ULS has changed interface language.

A default font will be set if a language or script has a problematic support history on a wide range of desktop computers and other devices. Even though most modern operating systems provide options to support a language or script well, this may require a user to take action first, such as installing software or changing the operating system settings. Our experience shows that a lot of users don't do this and give up, and we want to provide a quick and automatic way to make the text readable.

Universal Language Selector only provides freely licensed fonts. We choose default fonts based on popularity of the fonts (eg: default font for a script in Linux distributions, widely used in portals in the language, etc.) and based on input from potential users. If the default font has a bug that prevents users from using it, we will try to use an alternate font if available. For this a valid bug report is needed in Phabricator with high impact.

What if the default font chosen is not the best one for the language? Can this be changed?[edit]

Actions on Universal Language Selector now has event logging, see the queries and data. This will allow developers to analyze user behavior and changes in settings. Based on user behavior and other metrics, certain future changes may surface.

This means that the input tool and font support in WMFs tools need to be integrated with the eventlogging system. Any change in default input method or fonts must be supported by the usage statistics: out of FontA, FontB, for a language LANG, if FontA is usage is greater than FontB, FontB should be the default font for LANG. If system font is mostly preferred for that LANG, then by default we need to disable the webfont. The same logic applies for input methods.

Can I disable the default font that ULS has chosen for my language?[edit]

If the language is well supported by Grade A browsers and operating systems, default option for fonts, input methods may be the ones provided by the system. Well supported means, the browsers and operating systems provide a bug free font and input method for that language by default (bundled with OS, not requiring special steps to install).

There does not seem to be a font for my language. How can I request for a new font to be included in ULS[edit]

You can file a bug on Phabricator requesting for a font to be added for your language.

It is expected that you will also provide suggestions about the fonts and point us to where we can find them.

It is advisable to also seek consensus from other members of your language community about inclusion of the new font.

What information will be necessary for a new font to be included into ULS[edit]

The name of the font

URL to the source of the font

License for the font that allows it to be freely used, distributed and modified.

This information can be mentioned in Phabricator when requesting for a font to be included.

I would like to write in a different language. How can I change the settings to do so[edit]

Sidebar: You can go to the 'Input Settings' section in the Language Settings panel and select a language displayed on the buttons or from the 'Language Selection' popup.

Keyboard menu: The languages are displayed as a list and a selection can be made from here.

I have chosen a language, but I still cannot write in that language. What could be wrong[edit]

When you select a language, you will be presented with a list of input methods for that language. If no input methods exist within ULS for that language the native keyboard on your local computer will be used for input. If input methods are not available through either of the two options, then you will not be able to write in the selected language.

I would like to change the keyboard for the language that I have chosen. How can I do that[edit]

The input method/keyboard options within ULS for a language are displayed as a list in both the Language Settings panel as well as in the keyboard menu from a text input box.

A default keyboard is selected for each language. To use a different keyboard, you can make a selection from this list.

I have a keyboard on my computer and I do not want to use the keyboard in ULS. Can I disable the ULS keyboard completely[edit]

The ULS input methods can be disabled in 2 ways:

From the sidebar: by clicking on the "Use native keyboard" button within the input settings option in the Language Settings panel

From the Keyboard menu: by clicking on "Use native keyboard" from the keyboard menu that is displayed when the user clicks on the keyboard icon from an input field (like the search field)

Can I disable the ULS keyboard for only 1 language, without disabling the ULS keyboard completely[edit]

Yes. To do so, please select 'Use Native Keyboard' from the drop-down menu that is displayed in the list of keyboards available for that language.

We assess this for each language separately. Preferably it is the most practical and useful for that language, according to a consultation with potential users, to be the first one. If the default input method has a bug that prevents users from using it, it will be disabled as preferred or default input method. For this a valid bug report is needed in Phabricator with high impact. Until the bug is resolved, the next available input method will be presented on top of the list.

What if the default input method is not the best one for the language? Can this be changed?[edit]

Can I set all the Language Settings from within my user preference page[edit]

Yes. To configure the language settings, navigate to your user preference page and click on the "More language settings" option in the "Internationalisation" section under the "User profile" tab.

Why can anonymous users not use Universal Language Selector to change their interface language[edit]

This option is disabled on Wikimedia wikis, because the Wikimedia cache infrastructure currently does not support this. We are looking into making this possible in the future. There is no timeline for this.